There are fewprescribedmaintenanceproceduresforexhaust gas recirculationsystems, but a watchfuleye can prevent a smallproblemfromgettingworse.
Whilemost of theearlyproblemshavebeenengineeredout of theexhaust gas recirculationsystemsontoday’scleandieselengines, corrodedcoolers, stuckvalves and otherproblemsstill plague owners of olderequipment. Keeping a closeeyeoutfortelltalesigns of impendingfailure can help a lot.
Vehicle performance, fuel efficiency and frequency of active regenerations are good status indicators. Adhering to a regular maintenanceschedule and addressingissues as soon as theyarise are vital forpreventingdamage to thevehicle.
Fleetsshould monitor coolantconsumption in theirrigs. Forexample, iftheyfindthey are addinghalf a gallon of coolant per week, butthere are no externalleaks, that’s a goodindication of an EGR coolerwithaninternalleak.
Watchforwhiteresidueontheoutletend of thecooler. Youwouldn’tnecessarily be able to see a coolantleak, butburntcoolantleaves a whiteresiduethat’s visible. Once youhavethecooler off theengine, you can physically test it and blowitout to removetheexhaustresidue, butthat’safterthe fact. In addition, elevatedsodium and potassiumlevels in theoil are indicative of coolantcontaminationthatcould be coming in throughthe EGR system.
Exhaust gas recirculation in dieselengines reintroduces exhaustsootthatnotonly can corrodevalves and coolerswhencondensationoccurs, but can alsomakethemremain open orcloseddue to excessivebuild-up of gummydeposits. Thesefailures are not ascommontodaydue to changes in componentdesign, alongwith ultra-lowsulfurdiesel fuel as theonlyoptionforfueling, whichgreatly reduces thecorrosion and depositbuildup.
On top of theregens, the DPF willprobablyrequire a physicalcleaningsometimeoveritslife, and usingtherightoils can preventprematurecontamination.
Ifthe EGR coolingsystem has performance issues, troublecodeswill be present so don´t ignore them. Ownersshouldpayattention to thesignalsthey are gettingfromtheblinkinglightsonthedashboard and havethesystemfixedimmediately to avoid more costlyrepairs.
These advices do not necessarily apply to all engine brands and models but they can sometimes be applied generally. With that in mind, truck owners can still stay out of deep trouble by watching the engine for changes in oil or coolant consumption, fuel mileage and performance. ETM